I've never had any luck with these so-called "new car" scented deodorizers. The actual "new car" smell is mostly comprised of the scent of new leather and plastic parts from the factory. I have managed to keep my car smelling mostly new by keeping the interior clean and detailed for the most part. My interior smells like leather since I condition the seats periodically to keep them soft. My mom's 2006 Lexus still smells like "new car" because she never eats in it and keeps it ridiculously clean.

When I bought my car in 2011 I don't think the AC had been used very much (came from up North). The first time I turned it on I got a blast of New Car showroom smell

+1 on condition leather I always get compliments saying they love how my car smells like leather